The Full Installation Service
Octopus provides a complete installation service, handling everything from the initial quote and survey to supply, removal of old equipment, installation, commissioning and aftercare support. If, like me, you’re looking for a turnkey solution, this comes as close as I’ve found.
However, it’s not yet a commercial off-the-shelf (COTS) product. Having gone through the conversion from a gravity-fed water system to mains supply, I found this was a bigger deal than expected. The pump itself has been great, and I highly recommend ASHPs.
Here’s my take on how things went with this new technology and bespoke installation.
The Quote
In May 2024, I saw an Octopus campaign on Facebook offering a “quick quote” for heat pumps and solar. I clicked through and received a quote almost instantly.
The following week, I had a pre-sales call with Octopus to go over details. The process involved a £500 fully refundable deposit (which is now down to £200) to get a heat loss survey. I decided to go for it. My 24-year-old 3kW Ideal system boiler was showing its age. Since I was planning a kitchen refurbishment and considering moving to a combi boiler in the airing cupboard, this seemed a more long-term option. Gas will be phased out in the next 25 years, so I didn’t want to be stuck with an obsolete gas boiler.
Though the wait time was expected to be up to three months, there was an opening the following week, so I booked it.
Why I Chose Octopus
I wouldn’t say I’m an Octopus fan, but I am a convert. I checked out founder Greg Jackson and his values, which I found aligned with my own. Having worked in high-tech and multi-billion-pound corporations all my life, I know all big companies have their downsides, but Octopus has been impressive. I’d been moved to Octopus from Bulb after they went bust. For anyone interested, there’s a great interview with Greg Jackson by Heat Geek, which gives insight into the company’s vision.
The Octopus service includes a pre- and post-contract insurance policy with HIES, electrical certification through NAPIT, and MCS certification, which grants access to the £7,500 Boiler Upgrade Scheme (BUS) via Ofgem. Given the horror stories of fly-by-night installers and local companies online, Octopus felt like a safe bet.
At this point, I broke from tradition and didn’t seek other quotes. I didn’t feel knowledgeable enough to make an informed choice, so, like picking wine by the label, I chose based on Octopus’s reputation.
The Survey
Not knowing much about heat pumps, I turned to the internet and came across Heat Geek, Renewable Heating Hub and Skill Builder on YouTube. It all seemed quite complex. I’m an engineer by trade and a project manager by occupation, so I’m comfortable with numbers. I even tried a few heat loss calculations through online radiator shops.
When the Octopus surveyor arrived, he spent about five hours on the survey. He went over radiator plans, room-by-room heat loss, the 50°C design flow temperature and cable routing. We also discussed the loft insulation, and placement of the ASHP and consumer unit. I felt reassured by the surveyor’s approach and the quality of his analysis.
The Results
Most of the discussion focused on my pipework. I live in a timber-framed, well-insulated 2000-built semi-detached home. Two years ago, I added 300mm of loft insulation. The old boiler was fitted with primary pipework that runs from the kitchen to the airing cupboard and loft, where there’s a header tank. The pipework is 10mm microbore, which Octopus allows as long as it’s barriered, which mine is.
After discussing the radiator plan, I signed the contract, and within a week, I had an install date for August – just two months away.
The Equipment
The heat loss survey was done with a design temperature of 22°C for bathrooms, 18°C for bedrooms and 21°C elsewhere, with an outside design temperature of -2.4°C. The survey showed a heat loss of 4.1kW. The surveyor recommended swapping six radiators, providing a total output of 4.6kW. Initially, Octopus specified a Daikin Altherma 4kW Monoblock with a 180L hot water cylinder. Later, I switched to the Cosy 6 and upgraded to a 250L cylinder, as recommended by MCS.
Pre-Installation Requirements
The only pre-installation task on my end was clearing a space for the pump in the garden. Octopus handled everything else, including a new EPC, BUS grant application and DNO approval for the electrical circuit. My EPC came back as a C rating, and the BUS grant was approved.
Cosy 6 Launched
After signing the contract, I was offered a swap to the Cosy 6, Octopus’s in-house unit. Given that the future of Octopus seemed to be in its own products, I decided to switch to the Cosy 6. I also upgraded to a 250L hot water cylinder to better meet my household’s needs.
Pre-install Setup
A week before installation, scaffolding went up so Octopus could run a cable from the new consumer unit through the loft to the ASHP. The scaffolding was up front and back, depending on where your installation needs it, and was taken down a few days after installation.
The Installation
Planned for five days, the installation took six. A team of plumbers and electricians arrived on day one with all the required equipment. The ASHP site was prepared with a hard-standing base instead of a soakaway. My pump’s site is close to the garage wall, making for a very short external pipe run.
Inside, Octopus installed the DHW cylinder, a 26L volumiser, a Fernox TF1 filter, ESBE diverter valve, expansion vessel and a by-pass valve. In the airing cupboard, they cleared out the old system, making it available for storage. Octopus also took care of all the installation waste.
Conclusions
The system was completed with thermostat and humidity sensors (one per zone; I have one zone with two sensors). The small, wireless sensors are discreet and functional. The Cosy Hub, which connects to Wi-Fi, was set up quickly and is straightforward to use. Though the app currently has basic functionality, the system defaults to weather compensation, which has kept our home warm.
In October and November, with outdoor temperatures around 7-11°C, the ASHP used 234.01kWh, delivering 964.32kWh of output with a SCOP of 4.12. The Cosy Tariff, with three off-peak slots daily, has also been beneficial.
Finally, I opted for the £9/month service plan (included free for the first year), covering annual maintenance.
The Octopus Cosy 6 ASHP – What is it?
The Octopus Cosy 6 Air Source Heat Pump (ASHP) runs on R290 (propane) refrigerant. This system has a 6kW output and is installed with a Cosy Hub controller, along with up to four thermostat and humidity sensors. For Octopus customers, it can be accessed in the Octopus App under “Devices.” Recently, Octopus also announced the Cosy 10, a 10kW version of the heat pump.
@wreckguru where was the heat pump finally installed, as in the final location?
@Mars it’s in the back garden, behind the attached garage. It faces the same way as the solar so 145 degrees SE and gets a bit of sun.
The DHW is the other side of the garage wall with a short flow/return about 50cm.
Your edited article looks good.
@wreckguru so the actual heat pump is not sited near a door or window?
@Mars well the house has both😂
To the left in this picture there is a door, to the right the kitchen window. A bit further down the wall an air brick.
A building surveyor passed the site for controlled zone. This was done during the swap from Daikin to Cosy.
Given I keep 10,000 L of medical grade oxygen at 220 bar in my garage I am not concerned at all about a tea cup of refrigerant in my garden.
@wreckguru can’t say I disagree with your assessment and choices. Just for clarity in light in light of this article and journey, did Octopus ever give you advice on positioning?
@Mars yes. For the initial assessment for the Daikin we basically ruled out all my thoughts and landed at the current spot.
When changing to Cosy the assessor needed more measurements and pictures before oking it.
The swap was done late in the day, just days after it was available and not confirmed till Thursday before the team arrived (after the scaffolding was up).
As sure as I can me this is #1 install (it is for this team😂)
Tech diver I take it?
Open or closed circuit.
@IRMartini inspiration ccr, since 2001 with 1000+ hours down to 130m👍
@wreckguru
Wow Serious stuff indeed 😎
This is just a small point, to get SCOP value you have to run it for a whole year. I think you mean COP.
App estimates SCOP from COP. I don’t know if it is using the rolling figures or something else, there is no info. I suppose that would make sense and would agree with your comment.
@wreckguru ‘Seasonal’ COP suggests that an accurate assessment requires that data is required from a full season, (and I would suggest that for truer figures, this should be from four full seasons). COP may be a measurement of any duration but obviously the longer the sample, the more meaningful it might be. Regards, Toodles.
@Toodles I assume, but have not checked, that the adjustment can be made empirically?
@wreckguru With Homely, the estimated COP has the rider that it is only as accurate as the data it is given to work with; I am very sceptical of claims for my system’s COP as I am reliant on the Daikin data obtained from the bog standard measuring equipment fitted as standard.
By the way, I am too lazy to note down my consumption and heating figures every few weeks and my Homely graphs don’t provide historic data so establishing my SCOP would be a PITA!
Should I be allowing +or- 5%, maybe 10% – even 20%? I really don’t know, but I am assuming that any errors are probably fairly consistently erroneous! Homely often reports my COP between 3.8 – 5.5 depending on OAT and I am heating to 22.5 degrees C 24/7. This reported figure may be inaccurate but I suppose comparative. As they say, GIGO. I would be very pleased if the figures could be confirmed as correct – but the bottom line is acceptable as far as we are concerned, we are comfortable and we can afford the bills. Mind you, I am all in favour of reducing the iniquitous ‘Spark Gap’ and paying a more reasonable price for my green energy! Regards, Toodles.
@wreckguru how has your COP been during these last few cold days?
3.46, so pretty decent I think?